diff options
Diffstat (limited to 'arch/x86/entry/common.c')
| -rw-r--r-- | arch/x86/entry/common.c | 33 |
1 files changed, 11 insertions, 22 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index d69d1b6e6c31..e79d93d44ecd 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -45,6 +45,8 @@ __visible void enter_from_user_mode(void) CT_WARN_ON(ct_state() != CONTEXT_USER); user_exit(); } +#else +static inline void enter_from_user_mode(void) {} #endif static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch) @@ -85,17 +87,6 @@ unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch) work = ACCESS_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY; -#ifdef CONFIG_CONTEXT_TRACKING - /* - * If TIF_NOHZ is set, we are required to call user_exit() before - * doing anything that could touch RCU. - */ - if (work & _TIF_NOHZ) { - enter_from_user_mode(); - work &= ~_TIF_NOHZ; - } -#endif - #ifdef CONFIG_SECCOMP /* * Do seccomp first -- it should minimize exposure of other @@ -344,6 +335,7 @@ __visible void do_syscall_64(struct pt_regs *regs) struct thread_info *ti = pt_regs_to_thread_info(regs); unsigned long nr = regs->orig_ax; + enter_from_user_mode(); local_irq_enable(); if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) @@ -366,9 +358,9 @@ __visible void do_syscall_64(struct pt_regs *regs) #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) /* - * Does a 32-bit syscall. Called with IRQs on and does all entry and - * exit work and returns with IRQs off. This function is extremely hot - * in workloads that use it, and it's usually called from + * Does a 32-bit syscall. Called with IRQs on in CONTEXT_KERNEL. Does + * all entry and exit work and returns with IRQs off. This function is + * extremely hot in workloads that use it, and it's usually called from * do_fast_syscall_32, so forcibly inline it to improve performance. */ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs) @@ -409,6 +401,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs) /* Handles int $0x80 */ __visible void do_int80_syscall_32(struct pt_regs *regs) { + enter_from_user_mode(); local_irq_enable(); do_syscall_32_irqs_on(regs); } @@ -431,12 +424,11 @@ __visible long do_fast_syscall_32(struct pt_regs *regs) */ regs->ip = landing_pad; - /* - * Fetch EBP from where the vDSO stashed it. - * - * WARNING: We are in CONTEXT_USER and RCU isn't paying attention! - */ + enter_from_user_mode(); + local_irq_enable(); + + /* Fetch EBP from where the vDSO stashed it. */ if ( #ifdef CONFIG_X86_64 /* @@ -454,9 +446,6 @@ __visible long do_fast_syscall_32(struct pt_regs *regs) /* User code screwed up. */ local_irq_disable(); regs->ax = -EFAULT; -#ifdef CONFIG_CONTEXT_TRACKING - enter_from_user_mode(); -#endif prepare_exit_to_usermode(regs); return 0; /* Keep it simple: use IRET. */ } |